Apparatus for lapping chains



May 18, 1965 L. MEYRAT 3,183,781

APPARATUS FOR LAPPING CHAINS Filed Nov. 7, 1963 2 Sheets-Sheet 1 FIG. 1

INVENTOR.

LUCIEN MEYRAT ATTORNEY.

May 18, 1965 1.. MEYRAT APPARATUS FOR LAPPING CHAINS 2 Sheets-Sheet 2 Filed NOV. '7, 1965 INVENTOR.

LUCIEN MEYRAT ATTORNEY.

United States Patent:

3,183,781 APPARATUS FOR LAPPING CHAINS Lucien Meyrat, Moudon, Switzerland, assignor to Meyrat & Luisoni, a firm of Switzerland Filed Nov. 7, 1963, Ser. No. 322,240 Claims priority, application Switzerland, Nov. 21, 1962, 13,639/ 62 Claims. (CI. 90-49) The subject of the present invention is an apparatus for working out a polished surface, such as of a chain, with a milling cutter having toothed cutters formed of diamond.

The expression chains is understood to embrace any type of chain, including a curb-chain, and more particularly jewelry chains. The lapping of such chains has normally been performed by hand, the operator holding the chain in the tensioned condition, section by section, upon an adequate support element with his left hand, and proceeding to-lap the chain thus tensioned with his right hand.

This method of working is of course slow and expensive, and does not permit regular working.

The aim of the present invention is to obviate these disadvantages.

The apparatus, according to the invention, is characterised by the fact that it comprises at least one pair of twin cylinders rotating freely with respect to one another, a return wheel, a driving device intended to exert a traction upon the chain, and a braking device acting thereon so that it remains tensioned, while the chain passes over one of the twin cylinders, then wraps the return wheel to pass back over the other twin cylinder, so that the two sides or strands located on the twin cylinders shall each have a different face applied against one of them; the mill Works on the two chain strands thus supported, so that the two faces of the chain are worked simultaneously.

The drawings illustrate in exemplary manner a form of construction of the subject of the invention.

FIG. 1 is a perspective view of a milling machine equipped with an apparatus for working chains.

FIG. 2 is an elevation view of the apparatus drawn to a larger scale.

FIGS. 3, 4 and 5 are sections of the apparatus taken along the lines III-III, IVIV, V-V respectively of FIG. 2.

FIG. 6 is a plan view of a detail of the apparatus, partly sectioned, and

FIG. 7 is a section of a detail taken along the line VII-VII of FIG. 2.

The apparatus shown comprises a frame 1 intended to be fastened to the table of a milling machine, namely, in the example illustrated, to the vertical table 2 of a vertical spindle milling machine 3.

The frame 1 supports, mounted for rotation thereon, a pair of rubber-covered twin cylinders 4 and 5 (FIGS. 2 and 3) which are adapted to rotate freely with respect to one another. Two pairs of twin wheels 6 and 7 are mounted idly on two shafts 8, each supported by a cullis 9 (FIGS. 2 and 6) which moves radially on the frame 1 with respect to the twin cylinders 4 and 5. Said two pairs of twin wheels are diametrically opposite with respect to twin cylinders 4 and 5, and the pressure which they exert on the latter can be regulated by means of screws 10 which are supported against angle pieces 11 fixed to the frame 1, and are screwed each into one of the cullises 9.

The frame 1 further supports a return wheel 12 adapted for free rotation (FIGS. 2 and 3), and a pair of twin return wheels 13 and 14 (FIGS. 2 and 7) likewise capable of free rotation.

The apparatus illustrated comprises a chain driving device constituted by two rubber-coated rollers 15 and 16 (FIGS. 2, 4 and 5), mounted idly each on an axis 17, 18 respectively. The axis 17 is fixed to the frame 1, whereas the axis 18 is adapted for vertical sliding with respect to a bracket 19 which is itself fixed to the frame 1. -A lever 20, articulated to the frame 1 at 21, is adapted to act by means of a link-rod 22 upon the axis 18 to raise the latter so as to space the roller 16 from the roller 15, or to restore it into the working position as shown, in which the two rollers are urged to contact one another, being resiliently urged by helical springs 23 interposed between the axis 18 and the bracket 19.

The two rollers 15 and 16 are both driven in rotation in mutually opposite directions by means of a motor, not shown, connected by a belt not shown to a pulley 24 keyed on a shaft 25 of the roller 15. Said shaft 25 further supports a toothed-pinion 26 which, when the rollers are occupying their working positions, meshes with a toothedpinion 27 keyed on a shaft 28 of the roller 16.

The apparatus further comprises a chain braking device constituted of two pairs of rollers 29 and 30 urged in mutual contact (FIG. 2). The two rollers 29, 29 are mounted idly directly upon the frame 1, whereas the two rollers 30 are each supported by an axis 31, itself mounted on a bracket 32 secured to the frame 1, similarly to the axis 18 and to the bracket 19 previously described. The rollers 30, 3!) are urged resiliently against the rollers 29, 29 by means of springs, not shown, similar to the springs 23. Two levers 33, which are articulated at 34 each to one of the axes 31 and are supported against the top face of the bracket 32, permit the rollers 30, 30 to be spaced from the rollers 29, 29 counter to their restoring springs.

The apparatus illustrated operates in the following manner:

The rollers of the braking device and of the driving device being set in a spaced position, a chain 35, represented by a chain-dotted line in FIG. 2, is engaged on the two rollers 29, 29 beneath the twin return wheel 13, and upon the twin cylinder 4 between the latter and the twin wheels 6, serving as a pressure wheel, to pass round the return wheel 12.

The chain then passes over the twin cylinder 5, between the latter and the twin wheel 7, serving as a pressure wheel, beneath the twin return wheel 14 and between the traction rollers 15 and 16. As soon as the chain is in position, the levers 20 and 33 are operated so that the rollers 16, 30 respectively urge the chain onto the rollers 15, 29 respectively. The two sides or strands of the chain, being thus maintained in contact, each with one of the two twin cylinders 4 and 5, each have a different face applied to one of said cylinders. The milling cutter in the form of a toothed cutter, the cutters of which are formed of diamond 36 (FIG. 1), then works the two strands of the chain located in juxtaposition and maintained by the two twin cylinders. The two faces of the chain are thus worked simultaneously.

The chain advances continuously, drawn by the driving rollers 15 and 16. The apparatus should be regulated so that the braking device and the two pairs of wheels 6 and 7 produce a sufficient tension of the chain on the cylinders 4 and 5.

The apparatus permits not merely flattening a chain made of round wires by working its two faces, but also permits forming thereon decorative motifs by working with appropriate tools, not to mention working with a plurality of tools simultaneously.

To this end, the case may be provided where the apparatus comprises a plurality of pairs of twin cylinders corresponding to a plurality of work stations.

What I claim is:

1. In an apparatus mounted upon a milling machine for continuously and simultaneously presenting the opposite faces of an elongated workpiece such as a chain in a supported manner to a milling cutter operatively associatecl with the milling machine, the combination of, a frame supported by the milling machine, a pair of adjacent coaxially-disposed twin cylinders journalled in said frame and being independently rotatable in opposite directions with respect to each otherfa return wheel journalled in said frame on an axis parallel with and spaced 7 fromvthe axes of the twin cylinders'of'said pair thereof, a driving means for driving the chain relatively to the twin cylinders of said pair thereof, and a braking device for tensioning the chain during entrainment thereof over one of the twin cylinders of said pair thereof and over said return wheel and returnably over the other one of the twin cylinders of said pair thereof with one face of the chain bearing upon one of and with the opposite face of the chain bearing upon the other of the twin cylinders of said pair thereof for presenting opposite faces of the supported chain to the milling cutter. V

2. In an apparatus as claimed in claim 1, said driving means comprising a pair of rollers urged resiliently against one another and driven in rotation in opposite directions between which the chain passes.

3. In an apparatus as claimed in claim 1, said braking device comprising at least one pair of rollers urged resiliently against one another and between which the chain passes.

4. In an apparatus as claimed in'clairn 1, including two pairs of wheels located on each side of the twin cylinders of said pair thereof'for urging the chain against the cylinders so that the chain is intimately applied to the cylinders.

5. v In an app'aratus as claimed in claim 1, including two pairs of wheels located on-ea'ch side of the twin cylinders of said pair thereof for urging thechain against the cylinders so that the chain is intimately applied to the cylinders, the pressure exerted by the wheels of said pairs thereof upon the cylinders being adjustable so as to permit regulating the tension of the chain on the cylinders;

References Cited by the Examiner UNITED STATES PATENTS WILLIAM W. DYER, JR., Primary Examiner, 

1. IN AN APPARATUS MOUNTED UPON A MILLING MACHINE FOR CONTINUOUSLY AND SIMULTANEOUSLY PRESENTING THE OPPOSITE FACES OF AN ELONGATE WORKPIECE SUCH AS A CHAIN IN A SUPPORTED MANNER TO A MILLING CUTTER OPERATIVELY ASSOCIATED WITH THE MILLING MACHINE, THE COMBINATION OF, A FRAME SUPPORTED BY THE MILLING MACHINE, A PAIR OF ADJACENT COAXIALLY-DISPOSED TWIN CYLINDERS JOURNALLED IN SAID FRAME AND BEING INDEPENDENTLY ROTATABLE IN OPPOSITE DIRECTIONS WITH RESPECT TO EACH OTHER, A RETURN WHEEL JOURNALLED IN SAID FRAME ON AN AXIS PARREL WITH AND SPACED FROM THE AXES OF THE TWIN CYLINDERS OF SAID PAIR THEREOF, A DRIVING MEANS FOR DRIVING THE CHAIN RELATIVELY TO THE TWIN CYLINDERS OF SAID PAIR THEREOF, AND A BRAKING DEVICE FOR TENSIONING THE CHAIN DURING ENTRAINMENT THEREOF OVER ONE OF THE TWIN CYLINDERS OF SAID PAIR THEREOF AND OVER SAID RETURN WHEEL AND RETURNABLY OVER THE OTHER ONE OF THE TWIN CYLINDERS OF SAID PAIR THEREOF WITH ONE FACE OF THE CHAIN BEARING UPON ONE OF AND WITH THE OPPOSITE FACE OF THE CHAIN BEARING UPON THE OTHER OF THE TWIN CYLINDERS OF SAID PAIR THEREOF FOR PRESENTING OPPOSITE FACES OF THE SUPPORTED CHAIN TO THE MILLING CUTTER. 